Bioscience Discovery, 8(3): 502-506, July - 2017 © RUT Printer and Publisher Print & Online, Open Access, Research Journal Available on http://jbsd.in ISSN: 2229-3469 (Print); ISSN: 2231-024X (Online) Research Article Range of morphological variations of the genus Corallodiscus Batalin (Gesneriaceae) from Indian part of Eastern Himalaya Susmita Roy1*, T.K. Paul2 and Sobhan Kr. Mukherjee3 1 Department of Botany, Netaji Nagar College for Women, Regent Estate, Kolkata 700092, West Bengal, India 2 Botanical Survey of India (Retired), Howrah 711202, West Bengal, India 3 Taxonomy and Biosystematics Laboratory, Department of Botany, University of Kalyani, Kalyani 741235, Nadia, West Bengal, India *susmitanncw@rediffmail.com Article Info Received: 05-06-2017, Revised: 28-06-2017, Accepted: 30-06-2017 Keywords: Corallodiscus, Gesneriaceae, Morphology, North-East India, Tribe Trichosporae Abstract The genus Corallodiscus Batalin belongs to the tribe Trichosporeae under the family Gesneriaceae. Altogether five species of Corallodiscus Batalin have been reported throughout the World of which only three species are found in India. These are C. bhutanicus, C. kingianus and C. lanuginosus. A detailed account of the range of morphological variations in Corallodiscus Batalin has been discussed here based on the herbarium specimens. Extensive variation of habit, leaf, peduncle and capsule has been pointed out among the three Indian species. All the species are provided with detailed description with a key to the specimens. INTRODUCTION The genus Corallodiscus was first described as Didissandra by Clarke under Cyrtandreae (Clarke, 1883). He mentioned 7 species under 4 sections, of which only one species (D. lanuginosa) was reported from India while rest of the species from Malay vigentes. Batalin first established Corallodiscus Batalin (Gesneriaceae) based on a specimen “C. conchaefolius” (Batalin, 1892). Craib reported 16 species but described them as Didissandra C. B. Clarke (Craib, 1919a, b). Ridley used the name Didissandra for another group of plants from Malay Peninsula (Ridley, 1905). That is why Burtt (1947) transferred all of Craib’s species to Corallodiscus. Burtt recorded 18 species in Corallodiscus (Burtt, 1947). Of these 16 species were from China and 2 viz., C. cooperi (Craib) B. L. Burtt and C. bhutanicus (Craib) B. L. Burtt from http://jbsd.in Bhutan. In the Flora of China, Wang et al., (1990) revised Corallodiscus based on Craib and Burtt’s taxonomy and reduced the 16 Chinese species to 9. Later in the English version of Flora of China, [Wang et al., 1998; Gao et al., 2012] further reduced the number of species from 11 to 5. Corallodiscus bhutanicus, C. conchifolius, C. cooperi and C. kingianus (Craib) Burtt were all retained and the remaining species were included in Corallodiscus lanuginosus. This genus has been placed under the tribe Didymocarpeae. The Eastern Himalaya is situated between 82.70°E and 100.31°E longitude and 21.95°N to 29.45°N latitude. Eastern Himalaya is drained by Brahmaputra river and its tributaries including Teesta, Manas, Kameng and Subansiri. High degree of precipitation makes this region one of the wettest of the world. 502 ISSN: 2229-3469 (Print) Susmita Roy et al., Characteristic plants in Eastern Himalaya are moisture-loving. The plants under the family Gesneriaceae are distributed in extremely wide range of habitat. Some species like Corallodiscus kingianus is distributed along a wide altitudinal range from sea level to nearly 5000 m (Weber, 2004). Requirement of high humidity seems to be one of the important factors for the dense vegetation of gesneriads along the stretches of Eastern Himalaya. Indian Part of Eastern Himalaya covering the states of Arunachal Pradesh, Assam, Manipur, Meghalaya, Mizoram, Nagaland, Sikkim, Tripura and West Bengal were selected as the study area. Extreme adaptive features and wide range of habitats are key to their varied morphological characters. The Eastern Himalaya is referred to the region lying between 82.70°E and 100.31°E longitude and 21.95°N to 29.45°N latitude. It is extended to a total of 524,190 sq. km. This region starts from the Kaligandaki Valley in central Nepal and extended up to northwest Yunnan in China. Bhutan, the northeastern states of India including Sikkim, hills in the northern part of West Bengal, southeastern Tibet and parts of northern Myanmar are also part of Eastern Himalaya. During our literature review we found a dearth of knowledge on the morphological features of the genus Corallodiscus from this part of Himalaya. MATERIALS AND METHODS Present work is based on critical examination of the herbarium specimens deposited on Central National Herbarium, Howrah (CAL), Botanical Survey of India, Eastern Circle, Shillong (ASSAM), Lloyd Botanic Garden Herbarium, Darjeeling (LBG) and Arunachal Pradesh Regional Centre, Itanagar (ARUN). RESULTS AND DISCUSSION Corallodiscus is a perennial stemless rosette herbs. Leaves many forming rosette structure, thick textured, glabrous to densely woolly; lamina lanceolate, obovate, elliptic or rhomboid, base broadly to narrowly cuneate; petiole flat, venation conspicuous. Inflorescence 1-many flowered axillary cymes; bracts absent; bracteoles occasionally present, very small. Calyx divided deeply nearly up to the base or fused halfway. Corolla tubular, 5-lobed, 2-lipped, upper lip 2lobed, lower lip 3-lobed, longer than upper lip, lobes equal, rounded or obtuse, lower lip with dense long hairs inside, blue or purple. Stamens 4, one http://biosciencediscovery.com long pair and one short pair, included; anthers confluent, dorsifixed, cohering in pairs at apices, dehiscing longitudinally; filaments inserted in lower half of tube, eventually coiled; staminode 1.Disc annular, bright orange. Ovary conical, passing abruptly into style; stigma equally or shortly bilobed. Capsule oblong or linear-oblong, either septicidal or loculicidal. Seeds very small, ellipsoid, reticulate. Systematic account of the genus Corallodiscus Batalin Corallodiscus Batalin Trudy Imp. S. Petersburgsk. Bot Sada.(Acta Hort. Petrop.) 12: 176. 1892; Didissandra Clarke, C. B. Clarke in Hook. f., Fl. Brit. India 4: 355. 1884; Kanzilal et al. Fl. Assam, 3: 395.1939; A. Mukherjee, et al. Pleione 2 (2): 155. 2008. Synonym: Didissandra Craib 1919, auct non C. B. Clarke. Type: Didymocarpus lanuginosus Wall. ex A. DC., Nepal, Wallich, N. 791 (S). Habitat and ecology: Growing on rocks and rockcrevices within forests or above the forest line from 700 m to 5000 m. Distribution: Corallodiscus with ca. 5 species is distributed inIndia, BHUTAN, CHINA, NEPAL and THAILAND. Out of 5 species of Corallodiscus, 3 are growing in Eastern Himalayan part of India. Here discussion would remain restricted only on the 3 recorded species from the study area. Artificial key to the studied species 1a. Peduncles, pedicels and calyx persistently wooly………………………….2. C. kingianus 1b. Peduncles, pedicels and calyx glabrous or glabrescent………………...........…………..(2) 2a. Leaves persistently hairy above; plants not stoloniferous…………...…..1. C. lanuginosus 2b. Leaves either hairy above or glabrous; plant stoloniferous……….………3. C. bhutanicus 1. Corallodiscus bhutanicus (Craib) B. L. Burtt Gard. Chron. Ser 3, 122: 212. 1947 Type: DotenaTimpu, Bhutan, 2438m, 31.7.1914, R. E. Cooper, 2508 (E002597491!) [Holotype] Small herbs, sometimes stoloniferous. Leaves rosette, 20 X 13 mm, ovate-lanceolate, elliptic, apex obtuse, base cuneate, margin entire or sub-entire, coriaceous, nerves nearly always impressed above, side veins 3-5 pairs, petioles 13-20 mm long. Peduncles 1-6 flowered, arranged in umbel. Calyx brown, glabrous, 5-partite, segments lanceolate or 503 ISSN: 2231-024X (Online) Bioscience Discovery, 8(3): 502-506, July - 2017 linear-lanceolate, apex obtuse, ca. 3.5 mm long, 1 mm broad. Corolla 7-5 mm long, blue, inner surface hairy, lobes oblong, apex rotundas. Stamens 4, cohere in pairs, filaments glabrous. Disc annular. Gynoecium sub-equal, style long, ovary a little long. Capsule ca. 16 mm long. Habitat: Rock crevices at an elevation of 4400 ft to 8000 ft. Distribution:India (West Bengal: Darjeeling.); BHUTAN. 2. Corallodiscus kingianus (Craib.) B. L. Burtt, Gard. Chron., ser. 3, 122: 212. 1947. Synonym: 1. Didissandra kingiana Craib, Notes Roy. Bot. Gard. Edinburgh 11(55): 259. 1919; 2. Corallodiscus grandis (Craib) B. L. Burtt Gard. Chron. 3, 122 (3180): 212.1947 3. D. grandis (Craib) B. L. Burtt Gard. Chron. 3, 122 (3180): 212.1947 4. D. rufa King ex J. D. Hooker, auct. Non C. B. Clarke Icon. Pl. 15(2): 30, Pl. 1437. 1883 Type: Yunnan, Forrest, G. 10855 (K0008981291!) Rosette herbs. Leaves lanceolate to ovate, petiolate, adaxially glabrous, rarely rust-brown centrally, abaxially densely rust-brown, woolly, 1.6-11 X 0.84 cm, margin sub-entire to crenulate, apex acute, 11.8 cm, purplish to blue and white, inside with two deep dark brown spotted striae on abaxial lip, outside glabrous. Adaxial stamens 3-4 mm; abaxial stamens 5-6 mm; staminode present. Pistil glabrous, ovary ca. 3 mm, style 3-6 mm. Capsule ovoid to oblong, 6-20 mm. Habitat: Rocks on slopes or in forests at an elevation of 2800-4800 m. Fl. and Fr.: June-September. Distribution: India: Sikkim; BHUTAN, CHINA. Exsicc.: Sikkim, Yam Dokcho, 1500 m, Aug 1904. Capt. H. J. Walton (LBG);Sikkim, Gyantge Clefts, 1300 m, 6.10.1923, YHb 7652 (LBG) 3. Corallodiscus lanuginosus (Wall ex DC) B. L. Burtt in Gard. Chron. Ser 3. 122:212. 1947. Hara in Fl. Eastern Himalaya. 1. 298: 1966; Didissandra lanuginosa, Kanzilal et. al., Fl. Assam, 3:395. 1939; Synonym: 1. Didissandra lanuginosa Kanzilal et. al., Fl. Assam, 3: 395. 1939. 2. Didymocarpus lanuginosus Wall ex R. Br. Cyrtandreae 118. 1839. Type: China, 06. 1907, E. H. Wilson 2170 (K000898116!) Rosette herbs. Leaves crowded, spathulate, sessile, 4.5-12X1.5-2.8 cm apex obtuse, base attenuated, margin entire or serrated, both surface hairy. Inflorescence axillary and terminal cymose cluster; bracts paired, free linear; peduncles 6-12.5 cm. Long; pedicels 0.5-1 cm. long. Flowers white or pale purple. Calyx lobes triangular, upto 3 mm. long, acute. Corolla 1-1.5 cm, varying from whitish to violet. Stamens 4 fertile, 2-3 mm. long, anthers peltate, cohering in two pairs. Carpel 1, Ovary sessile, globose. Capsule sessile with persistent calyx, 1.2-3 cm. long, sickle-shaped, beaked. Habitat: Moist rock, on hill slopes. Fl. and Fr.: July – September Figure 1. Herbarium specimen of Corallodiscus Figure 2. Herbarium specimen of Corallodiscus bhutanicus (Craib) B. L. Burtt preserved in Lloyd lanuginosus (Wall ex DC) B. L. Burtt Lloyd Botanic Garden Herbarium, Darjeeling Botanic Garden Herbarium, Darjeeling http://jbsd.in 504 ISSN: 2229-3469 (Print) Susmita Roy et al., Distribution: India: West Bengal (Darjeeling, Sikkim), Himachal Pradesh, Uttar Pradesh; NEPAL, BHUTAN, CHINA, THAILAND. Exsicc: , Meghalaya, K & J Hills, Elephant falls, 13.7.1939, G. K. Deka 18443 (ASSAM); Arunachal Pradesh, Kameng F. D., Tawang to Zang, 31.5.1957, G. H. Bhaumik 60335 (ASSAM); West Bengal, Darjeeling, Kaydong, 7000 m, May 1885, G. King (LBG); West Bengal, Darjeeling, Rimbik to Palmanjira, 10.10.1941, Dr. K. Biswas 5779 (CAL); Sikkim, Teesta Valley, 3800 ft (1158.24m), 5.7.1909, Smith & Cave 822 (CAL); Meghalaya, Khasia, Kullong, 5800 ft (1767.84m), 23.08.1885, C. B. Clarke 40014 (CAL); Sikkim, Saiboo-la, 1500 ft (457.2m), Aug 1886 G. King (CAL) Table 1. Comparative morphology of Corallodiscus bhutanicus, C. kingianus and C. lanuginosus. Character Habit C. bhutanicus Rosette herb without stolon C. kingianus Rosette herb without stolon C. lanuginosus Rosette herb with stolon Leaves Lamina ovate lanceolate to elliptic, almost sessile, both surface densely woolly Lamina broadly rhombic lanceolate to lanceolate, petioled, upper surface glabrous or rarely rust-brown woolly near base of the midrib Lamina broadly obovate to elliptic, petioled, upper surface glabrous to densely villous, lower surface brownish pubescent to white to brownish woolly Peduncles Glabrous to glabrascent Densely rust-brown woolly Glabrascent to brownish woolly Capsule Oblong and more crowded Ovoid to oblong Narrowly oblong and less crowded. Fig: Corallodiscus lanuginosus (Wall. ex DC) B. L. Burtt, (a) Habit, (b) Calyx, (c) Corolla, (d) Stamens. http://biosciencediscovery.com 505 ISSN: 2231-024X (Online) Bioscience Discovery, 8(3): 502-506, July - 2017 CONCLUSION The result of the study reveals that the genus Corallodiscus Batalin is widespread across China and adjacent countries to the West and South Asia like India, Nepal, Bhutan and Thailand with C. lanuginosus (DC) B. L. Burtt. covering the entire range of distribution. Worldwide the genus comprises of about 5 species of which three are found in India (C. lanuginosus, C. kingianus and C. bhutanicus). Indian species are dominated in the Eastern Himalayan region excepting C. lanuginosus which is widespread with a variety (C. lanuginosus var minuta Haines) occurring in Bihar. Out of the three species recorded from India two have been recorded from China, 3 from Bhutan, 1 from Thailand and 1 from Nepal. The plants are rosette herbs with or without stolon (C. bhutanicus) growing in cliffs and rock faces. In India Corallodiscus Batalin is restricted to few states: C. bhutanicus in West Bengal (Darjeeling); C. kingianus in Sikkim, West Bengal (Darjeeling) and C. lanuginosus in West Bengal (Darjeeling), Sikkim, Arunachal Pradesh, Meghalaya, Himachal Pradesh and Uttar Pradesh. There is no record of C. kingianus from studied herbarium. It has been recorded and described only from literature. Rare collection of C. bhutanicus has been recorded only from Lloyd Botanic Garden Herbarium. Presently 3 species of Corallodiscus Batalin from Eastern Himalaya, India have been revised under 2 sections viz., Boeoides and Cyrtandroides. Section delimitation was done on the basis of habitat characters, venation pattern and presence or absence of stolon. Species delimitation has been made on the basis of leaf characters, capsule characters, nature of peduncle, nature of hair on the upper surface of the leaf. Extensive study reveals gradual declination of the species. Conservation is necessary for the genus. Acknowledgement The authors are thankful to the Directors of the Herbarium of CAL, ARUN, ASSAM and Lloyd Botanic Garden Herbarium, Darjeeling for giving permission of accessing herbarium. The authors are also thankful to Head of the Department of Botany, University of Kalyani for encouragement. The first author is thankful to the Principal, Netaji Nagar College for Women for his constant encouragement and support. REFERENCES Batalin A, 1892. Trudy Imperatorskago S.Petersburgsk Botaniceskago Sada. Notae de Plantis Asiatics, 12(6):176-177. Burtt BL, 1947. Didissandra and Corallodiscus. Gardeners Chronicle, series 3, 122:204, 212. Craib WG, 1919a. Didissandra and allied genera in China and N. India. Notes from the Royal Botanic Garden Edinburgh, 11:255-268. Craib WG, 1919b. Gesnecearum novitates. Notes from the Royal Botanic Garden Edinburgh, 11:233254. Kanjilal UN, Das A, Kanjilal PC and De RN. 1939. Flora of Assam. 3:388-400, Government of Assam, India. Ridley HN, 1905. The Gesneriaceae of the Malay Peninsula. Journal of the Straits Branch of the Royal Asiatic Society, 44:1-92. Wang WT, Pan KY, Li ZY, Weitzman A and Skog LE. 1998. Gesneriaceae. In ZY. Wu and PH. Raven [eds.], Flora of China, 18:244-401. Science Press, Beijing, China and Missouri Botanical Garden Press, St. Louis, Missouri, USA. Weber A, 2004. Gesneriaceae. In K. Kubitzki (ed) The Families and Genera of Vascular Plants. VII: 63-158. Flowering Plants Dicotyledons Lamiales (except Acanthaceae including Avicenniaceae), ed. J.W. Kadereit. Springer, Berlin. Gao L-M, Zhang Z-R, Zhou P, Möller M and Li D-Z, 2012. Microsatellite markers developed for Corallodiscus lanuginosus (Gesneriaceae) and their cross-species transferability. American Journal of Botany, 0:e490-e492. How to Cite this Article: Susmita Roy, T.K. Paul and Sobhan Kr. Mukherjee, 2017. Range of morphological variations of the genus Corallodiscus Batalin (Gesneriaceae) from Indian part of Eastern Himalaya. Bioscience Discovery, 8(3):502-506. http://jbsd.in 506 ISSN: 2229-3469 (Print)